1134 



REPORT OF NATIONAL MUSEUM, 1898. 



of the bead, dark purplisli-browii, of which color is also the space in 

 front and below the eyes. General color above dull dark chestnut 

 brown. On each side a series of twenty or thirty narrow vertical pur- 

 plish black bars one or two scales wide. Of these sometimes two con- 

 tiguous to each other on the same side are united above into an arch, 

 inclosing a spuco the center of which is rather duskier than the ground 



color; at others corresponding 

 bars from the opposite sides unite 

 and form half-rings, encircling the 

 body ; sometimes there is a lighter 

 shade bordering the dark bars. 

 Beneath black, blotched with yel- 

 lowish white. 



Baird and Girard record a speci- 

 men from Prairie Mer Eouge, 

 Louisiana, which had 140 gastros- 

 teges, 24 single and 21 double 

 urosteges. 

 B Measurements. — Length, 22f 



t inches; tail, 3i inches. 



In some specimens from western 

 Texas the superior labial plates 

 have a slight anterior position at 

 the expense of the second, which 

 is somewhat narrowed, especially 

 toward the labial border. In one 

 specimen (Cat. No. 822) this plate 

 is a triangle with the apex down- 

 ward, which does not reach the 

 labial border. In another it enters 

 theborder by a narrower'edge than 

 in typical forms. The character is 

 thus variable. The same disi)lace- 

 ment of the labials brings the 

 fourth labial into the border of the 

 orbit by a short edge in some 

 specimens, but this character is also quite inconstant. On such speci- 

 mens Baird and Girard proposed their To.vkophis pugnax^ but under the 

 circumstances the form does not seem to be distinguishable. 



In the young of the Ancistrodon piscivorus the colors are brighter, 

 more contrasted, and the pattern therefore more distinct. 

 The "moccasin" or "cotton mouth" is a well-known inhabitant of the 



